Field
The present disclosure relates generally to information-centric networks (ICNs). More specifically, the present disclosure relates to an ICN architecture that does not maintain per-Interest forwarding states.
Related Art
The proliferation of the Internet and e-commerce continues to fuel revolutionary changes in the network industry. Today, a significant number of information exchanges, from online movie viewing to daily news delivery, retail sales, and instant messaging, are conducted online. An increasing number of Internet applications are also becoming mobile. However, the current Internet operates on a largely location-based addressing scheme. The two most ubiquitous protocols, the Internet Protocol (IP) and Ethernet protocol, are both based on end-host addresses. That is, a consumer of content can only receive the content by explicitly requesting the content from an address (e.g., IP address or Ethernet media access control (MAC) address) that is typically associated with a physical object or location. This restrictive addressing scheme is becoming progressively more inadequate for meeting the ever-changing network demands.
Recently, information-centric network (ICN) architectures have been proposed in the industry where content is directly named and addressed. Content-Centric Networking (CCN), an exemplary ICN architecture, brings a new approach to content transport. Instead of having network traffic viewed at the application level as end-to-end conversations over which content travels, content is requested or returned based on its unique name, and the network is responsible for routing content from the provider to the consumer. Note that content includes data that can be transported in the communication system, including any form of data such as text, images, video, and/or audio. A consumer and a provider can be a person at a computer or an automated process inside or outside the CCN. A piece of content can refer to the entire content or a respective portion of the content. For example, a newspaper article might be represented by multiple pieces of content embodied as data packets. A piece of content can also be associated with metadata describing or augmenting the piece of content with information such as authentication data, creation date, content owner, etc.
In existing interest-based ICN approaches, such as CCN or Named Data Networking (NDN), routers (or nodes in the network) need to maintain a Pending Interest Table (PIT) in order to store the Interest state, including the interfaces from which Interests for specific named data objects (NDOs) are received and the interfaces over which such Interests are forwarded. The PIT allows NDOs that satisfy Interests to follow the reverse path back to the original requester while hiding the identity of the original requester. However, as the number of Interests handled by a router grows, so does the size of the PIT, which can be many orders of magnitude larger than the size of traditional routing tables because routers handle far more Interests than the number of routers in a network.